6-Aminomethyl-6,11-dihydro-5H-dibenz[b,e]azepin is an important compound as a raw material of medicines. Known as production methods of the aforesaid compound is a method in which 6-cyano-11H-dibenzo[b,e]azepin is allowed to react, in THF, with lithium aluminum hydride and aluminum hydride prepared employing 100 percent sulfuric acid (Arzneim.-Forsch., 40, 4, 440, (1990) and Japanese Patent Publication No. 3-66311.
However, the aforesaid synthesis method necessitates an anhydrous THF solvent which results in heavy load in terms of cost and includes time consuming operations such as filtration of an excessive amount of inorganic substances deposited after the reaction.
Further, known is a method in which 6-phthalimidomethyl-6,11-dihydro-5H-dibenz[b,e]azepin is isolated, which is formed by hydrogenating 2-(1H-dibenz[b,e]azepin-6-ylmethyl-1H-isoindole-1,3(2H)-dione employing formic acid as well as palladium carbon, and subsequently is subjected to hydrazine decomposition. (Japanese Patent Publication Open to Public Inspection No. 4-346988).
However, since this method uses hydrazine, which is a carcinogenic substance, in the industrial production, operators' safety becomes a problem. Further, isolation is required between the hydrogenation and the hydrazine decomposition. During industrial scale production, it is well known that a decrease in isolation is desirable.